Genomics to Solve Agricultural Problems: Nematodes as an Example

Pickling Cucumber Improvement Committee Meeting Abstract

David M. Bird

Department of Plant Pathology, North Carolina State University

Plant breeders typically move single genes that give a desirable trait to develop better crops. More elaborate breeding schemes permit small sets of genes that collectively contribute to a trait (quantitative loci), also to be moved into useful cultivars. Molecular tools have been developed to assist breeders in following the movement of genes (marker assisted breeding). The main advantage of these techniques is that cultivar development can be more rapid. In the last decade, genes conferring useful traits (especially pest-resistance) have been isolated, and it is hoped that such genes might be moved from crop-to-crop using transgenic technologies. For example, efforts are underway to move the tomato Mi gene (which confers nematode resistance) into other crops. Unfortunately, this has not yet been successful. Recently, a new set of research tools have been developed that permits the simultaneous study of essentially all the genes in an organism (be it plant, animal, or microbe). This new approach is termed Genomics, and is beginning to revolutionize biology. Genomics allows scientists to study very complex biological interactions (such as occur when a pathogen attacks a plant) without having to make guesses about what might be important. As a result, we can look at everything. My group is using a genomics approach to study plant-parasitism by root-knot nematodes.

Root knot is the most important disease of cucumber, and it is likely to increase in importance as the use of methyl bromide as a soil fumigant is phased out. The entire cucumber germplasm collection has been searched for resistance to the major nematode species (Meloidogyne incognita), and no resistance has been found, hindering traditional breeding approaches. We are attacking the problem on two fronts. We first wish to identify every gene in the nematode as an approach to identify targets for new, environmentally-safe, and affordable nematicides. Second, we will identify every plant gene that responds to the nematode to identify targets for transgenic intervention. In essence, we hope to supply the breeders with novel forms of resistance that can be used to develop the cultivars of the future.

For further information, contact:

  • Dr. David M. Bird, Associate Professor
  • Department of Plant Pathology
  • North Carolina State University, Raleigh, NC 27695-7616
  • Telephone: 919-515-6813; Fax: 919-515-9500
  • E-mail:

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